IX on PK

If there is no index existing on a table, will a primary index be created implicitly when a primary key constraint is added?

Yes, atleast in SQL Server and Oracle.

Thank you for your response.

In SQL query analyzer Object Browser window, the primary ix will not show if it is not created explicitly.

If you use Enterprise Manager and go to Design - manage indexes windows, you will see it.

Or you can verify it by looking at sysindexes table.

Thanks again.